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Levels of VSH genetics

I came upon this article earlier today, which states that VSH behavior is polygenic and revolves around approximately 7 additive genes. It goes on to say that ~50% VSH genes appears to be optimal, as 100% VSH bees tend to be overzealous (I assume) and therefore do not rear brood very well at all, thus requiring that the colony be sustained by foreign brood.

This all sounds nice, but it rises the question... how does one estimate the level of VSH genetics in a queen? How can one tell that the queen is 0%, 70%, 100%, etc.? And would I be correct in understanding that there are about 14 levels of VSH, from the total absence of VSH genetics to having the 7 responsible genes being homozygous?

Re: Levels of VSH genetics

A friend of mine has been producing queens from VSH breeders for several years - all of his hives from honey producers on down to drone hives and mating nucs are now headed by descendants of II VSH breeder queens and have been for some time. It would be reasonable to assume that the wild population in his area has some component of VSH as well. So, probably there is as much VSH in his operation as one could reasonably expect in open mated bees.

But there are still hives that do better or worse. You still do mite counts and replace queens in under performing hives. Nothing really changes except that with the same cultural practices (whatever they might be) mites won't be as problematical as they might be otherwise. So they just do better in general on average.

As you might imagine I use some of his queens (and cells) and they are very good quality, but not magical bees. Their performance still has as much to do with my husbandry as any of the others.

Re: Levels of VSH genetics

I'm thinking along the lines of II, though. Therefore, it seems preferable to have one parent with 100% VSH genes, and the other with 0%, in order to have a constant result of 50% in the daughters. Any other combination may average out to around 50%, but there could be workers with as little as 0% and as much as 100%, neither of which sound desirable.

The frozen brood tests I know of will allow the rating of VSH behavior at the hive level, but not at the queen level. You could have a queen with 0% VSH genes, and from what I hear, her daughters will do great as long as their fathers have a high % of the genes themselves. But if you used her drones, you wouldn't actually be transmitting any of those VSH genes you want to stock you are crossing it to.

Re: Levels of VSH genetics

So you want to be able to artificially inseminate with the drone offspring of a confirmed 100%VSH x 0%VSH? To a confirmed 50% VSH breeder queen?

Also gives more credence to promoting drone vitality.

Essentially, I'd want to develop one or more lines with 0% VSH, and one or more with 100% VSH, in order to instrumentally inseminate them to each other to have a guaranteed 100% of the offspring daughters having 50% of the VSH genes.

So it seems to me like I'd need to import a 100% VSH queen if I ever want to develop one, assuming I have no VSH bees in my apiary (I do, but for practicality, it's easier to pretend that I don't). Because if we run on the hypothesis that VSH genes are additive and concern at least 7 different genes on exactly seven different loci, then I could import a "50%" VSH queen, which could in reality have 3 homozygous VSH genes and one heterozygous VSH gene, in turn meaning that, on the long term, in a closed breeding program, the highest VSH gene % I could aspire to would be 57,24% (4 homozygous VSH genes). The other VSH genes for the other 3 loci would never manifest itself in my apiary, because it is not native to it, and was not imported with the original VSH queen.

A large import volume from different VSH breeders should, in theory, allow me to import all of the VSH genes that are being bred. However, without a method to measure this progress, one would have to pursue this avenue for a considerable period of time, purifying the imported genetic pool from all of the undesirable genes for one's climates and other needs. Simply importing a ton of VSH queens, without being able to measure for sure, would be very time and resource consuming project.

Now, I know the answers probably lie in the project papers themselves, which I do intend to read in the coming days, but I thought it could be interesting to throw this out there and see what others think.

Re: Levels of VSH genetics

After some further reading, such as this article by dr. Harbo and a few other documents regarding these trials, it seems to me like the key to estimating and improving the VSH genetics is through single-drone matings and the calculation of the mite-oviposition ratio (OVR).

Essentially, you take your best VSH queen, you breed a bunch of drones from her, you then single-mate them to non-VSH queens, and you measure the OVR in those offspring colonies. The distribution should be able to give you a pretty good estimates of how many VSH genes you have in your stock. Alternatively, you could also just skip this step and just select for the lowest OVR.

Re: Levels of VSH genetics

Originally Posted by Dominic

I came upon this article earlier today, which states that VSH behavior is polygenic and revolves around approximately 7 additive genes. It goes on to say that ~50% VSH genes appears to be optimal, as 100% VSH bees tend to be overzealous (I assume) and therefore do not rear brood very well at all, thus requiring that the colony be sustained by foreign brood.

This all sounds nice, but it rises the question... how does one estimate the level of VSH genetics in a queen? How can one tell that the queen is 0%, 70%, 100%, etc.? And would I be correct in understanding that there are about 14 levels of VSH, from the total absence of VSH genetics to having the 7 responsible genes being homozygous?

Finally, are there any breeders that have 100% VSH queens to sell?

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This may help you:
What is VSH?

USDA ARS scientists Dr. John Harbo and Dr. Jeffrey Harris at the Honey Bee Breeding Laboratory in Baton Rouge, Louisiana, have defined and tested a trait of the honeybee which appeared to suppress mite reproduction (SMR). Recently it has been better defined as "varroa sensitive hygiene (VSH)." This is a form of behavior where adult bees remove pupae that have reproductive mites but do not disturb pupae that have mites that produce no progeny.
Recent research done under real world beekeeping conditions with Alabama beekeepers clearly show the value of VSH bees. The resistance to Varroa mites was significantly better than all other bees in the study without sacrificing honey production. These bees have proven their value to American beekeepers. The time has come for you to take advantage of this remarkable line of bees.
Dr. Harbo and Dr. Harris proved the effectiveness of the VSH trait by exchanging queens between resistant and susceptible colonies. Each time a resistant queen was put into a susceptible colony, the mite population went down. On the other hand, every time a susceptible queen was placed in the resistant colonies, the mite population increased.

Recent studies by Dr. Spivak and Dr. Harbo have shown that the SMR trait might be best described as a "varroa-sensitive hygienic behavior". VSH bees remove mites that have started to reproduce. The reproduction of mites triggers their removal by the bees. The only mites left in the cells are non reproductive or sterile. So there is evidence for selective removal of reproductive mites from brood cells.

A goal of the USDA SMR Project is to distribute the VSH trait for resistance to Varroa mites to queen breeders around the country. The object is to cross these bees with beekeeper's own well adapted stock. This will maintain the genetic diversity of American bees while enhancing this important trait. Once in the hives of beekeepers, further selection and improvement can be made for honey production, other disease resistance mechanisms, and other beneficial traits. Recent tests have shown that VSH queens retain an acceptable level of mite resistance when they are free mated to unselected drones.

The best way to get the maximum amount of the trait into a line of bees is to begin with a pure VSH breeder queen so her daughters mate with your local drones. Workers from pure VSH queens have a hyper-hygienic behavior where their workers remove more brood than is necessary or desirable. This will show up as a deterioration of the breeder's brood pattern after about six weeks. The regular addition of frames of sealed brood from other colonies will keep the colony strong. Daughters queens of pure VSH breeders who are out crossed by natural mating have good brood production and an acceptable level of mite resistance.

The VSH trait has proven to be extremely effective at controlling Varroa. It holds great promise as a permanent solution, but the work is not yet finished. There is still considerable variation in crosses with different lines of bees, and so should still be thought of as as a work in progress.With the recent retirement of Dr. Harbo from the bee lab, Dr. Bob Danka , Dr. Jeffrey Harris and others at the USDA Baton Rouge Bee Lab are carrying on the work.

Re: Levels of VSH genetics

Re; VSH stock/genetics.

HARBO BEE CO.

Our varroa-resistant breeding stock

A decision that every queen producer has to make is: Which queen should I graft from?

Put the burden of that choice on us. If you receive a breeder queen from us, you will be sharing our best breeding stock and benefit from our experience and knowledge of selecting bees for mite resistance. You can be confident that the daughters of our VSH breeder queen will produce varroa-resistant colonies (even when mated at your location to drones that may not carry the VSH trait for mite resistance).

Each breeder queen we sell is produced from a parent colony that has expressed the highest level of the VSH trait. The queen is then artificially inseminated with semen collected from drones from a different mite-resistant colony. Before we release a queen for sale, she is allowed to lay for about two weeks to be sure that she has good brood production, a solid brood pattern, no sign of disease, and for the absence of queen cells. The queens are examined for physical injuries such as imperfect legs and foot pads (arolia).

Re: Levels of VSH genetics

[QUOTE=fraz

Nitrogen freezing and pinpricking of lavae is a test for hygenic behaviour rather than VSH they are two different things.[/QUOTE]

Yes they are different, but there is a 70% correlation between the Hygentic trait and the VSH trait. And from my understanding most all colonies that express the VSH trait also possess the Hygentic trait (somebody correct me if I misunderstood this).

Re: Levels of VSH genetics

Dominic if you have read Harbo you must also have read how he tests for levels of VSH.

It's about removing Pupae and counting the mites within the cell. the more mites that are single female mites rather then mite familys the more the VSh trait is being expressed.

Nitrogen freezing and pinpricking of lavae is a test for hygenic behaviour rather than VSH they are two different things.

As another said, though, the two seem correlative, and the hydrogen tests seem to work well on VSH stock. Of course, hygienic doesn't mean VSH, but once you know you have VSH genes, the brood freeze tests can give a good idea. But as you say, the OVR is the only measure allowing the true testing of VSH, which I was not aware of when I started the thread for I had not yet read dr. Harbo's texts, and most breeders I read up on talked about the frozen brood test to see how good their VSH stock is.

Originally Posted by BEES4U

Re; VSH stock/genetics.

HARBO BEE CO.

Our varroa-resistant breeding stock

A decision that every queen producer has to make is: Which queen should I graft from?

Put the burden of that choice on us. If you receive a breeder queen from us, you will be sharing our best breeding stock and benefit from our experience and knowledge of selecting bees for mite resistance. You can be confident that the daughters of our VSH breeder queen will produce varroa-resistant colonies (even when mated at your location to drones that may not carry the VSH trait for mite resistance).

Each breeder queen we sell is produced from a parent colony that has expressed the highest level of the VSH trait. The queen is then artificially inseminated with semen collected from drones from a different mite-resistant colony. Before we release a queen for sale, she is allowed to lay for about two weeks to be sure that she has good brood production, a solid brood pattern, no sign of disease, and for the absence of queen cells. The queens are examined for physical injuries such as imperfect legs and foot pads (arolia).

Re: Levels of VSH genetics

Which brings me another question... The Primorsky bees are reputed to be more tolerant/resistant to the varroa mites. Is this because they have the VSH genes, or is it due to other factors only (such as grooming behavior)? Thus, if I crossed a "pure" Primorsky queen with breeder VSH queen drones, would I get 50% VSH offspring or 50-100% VSH offspring?